I would say if you can do 130 miles w/ 15,000 ft of climbing you are more than on pace to do a 1 day STP. The main training difference is fast flat riding instead of climbing. Cruising at 22-24 in a paceline is a much different ride than 8mph grinding up a mtn pass. Check out cascade.org for a training guide and rides. They have more than one ride series that builds up to doing a one day stp.